1. Field of the Invention
This invention relates to a signaling device for alerting deaf persons to various conditions, including dangers as well as more mundane situations, such as a phone call or the presence of a visitor.
2. Description of the Prior Art
For most of the human population, alerting devices for the home and for commercial facilities such as hotels, rely primarily on sound to alert persons within audible range to the occurrence of certain events requiring the persons' attention, for example certain dangers. Smoke alarms produce a loud, high pitched or pulsating sound to alert persons to the danger of fire; typically doorbells rely on chimes or bell sounds to signal a presence at the door; alarm clocks employ buzzers or bells, often driven mechanically or electromechanically; and telephones utilize a bell, often driven electromagnetically. The audible alarm method as a means for alerting persons having impaired hearing of course is, in most cases, ineffective and unsuitable. As means of addressing this problem, numerous alerting systems have been developed to rely on other indicators more readily noticed by the persons to be warned.
U.S. Pat. No. 3,786,628 to Fossard et al discloses a warning device particularly useful for the deaf or partially deaf which comprises a mechanical vibration generator responsive to signals produced by a trigger signal generator. The trigger signal generator is actuated by any of a plurality of external sources of sound, namely, an alarm clock, a doorbell or a car horn. The alerting device produces mechanical vibrations of a fixed or variable frequency, which mechanical vibrations are sensed tactilely by the person to be alerted.
U.S. Pat. No. 4,380,759 to Sulkowki et al discloses an apparatus for alerting those having impaired hearing which utilizes a vibrating reed which is actuated by triggering signals from a radio receiver. The device resembles a portable "beeper". The "beeper" radio receiver is equipped with an antenna and is equipped with reception means for receiving alarm signals such as those emitted by a smoke alarm having a radio output signal. When activated, the vibrating reed pulses and is sensed by the person with impaired hearing due to tactile contact.
U.S. Pat. No. 4,553,138 to Nakanishi et al discloses an alarm system which comprises a means for sounding an alarm, with a tactile indicator for a disabled person. The system is particularly suited for bedridden persons who cannot call for help, but require a device for alerting others of their difficulty. The alarm system includes a stationary body and a movable body, wired to the stationay body, with the stationary body being equipped with sensing means. An alarm means on the stationary body is activated in response to the sensing means. The movable body, which is attached to the disabled person, is equipped with a vibration-type buzzer which, when activated, effects a vibration which can be felt by the person to confirm the alarm status, which can be initiated by the disabled person. The remote unit contains a control switch which may be activated by the person to initiate an alarm which will alert others to the call from the person, and this "calling for help" status is fed back to the impaired person by the tactile indicator.
Tactile systems are effective non-auditory alarms but require a vibratory output device in contact with the person to be signalled. These devices have sometimes been preferred over devices having visual alarms because the person to be alerted may be unable to see a light flashing on an alarm device or the like. However, they are not generally available devices and generate expenses. Moreover, many such devices must be wired to the person to be alerted, which is unacceptable.
It is also possible to employ visual signalling as an alternative to auditory signalling. In order to be effective, for example, to wake a sleeping hearing-impaired person, the power level of the visual signalling must be substantial. The flashing of a panel light on an alarm device is unlikely to suffice. However, the flashing of a room light normally is enough stimulus to wake a hearing-imparied person, who is relatively more attentive to visual stimule than persons with nominal auditory acuity.
U.S. Pat. No. 3,810,170 to Zinsmeister disclosed a visual signaling system for the deaf which is effected through a high intensity lamp such as a strobe lamp. The visual signaling system is actuated via an alarm system equipped with a control panel having various distinct indicator means to indicate fire, a call at the door, etc. Inasmuch as the light (although bright) is a small panel lamp, the person to be alerted should be looking at or toward the area of the flashing light in order to notice it, because the light is directly on the control panel rather than a widely-broadcast light source such as a room light, table lamp or the like.
U.S. Pat. No. 4,180,810 to Muncheryan discloses a device for awakening a sleeping person which is particularly adapted for persons with impaired hearing. In the background portion of the patent it is mentioned that flashing lights had been tried to visually alert or signal those persons of impaired hearing to dangers and other situations, but that such visual signaling often was ineffective where the person was asleep or facing away from the flashing light. Another problem mentioned with respect to with visual signaling was that such visual signaling also alerted or awakened others. The patent therefore featured to the physical tactile stimulating signals method, to awaken both deaf persons and persons of normal hearing when asleep. The physical stimulating signal was activated by a receiver capable of distinguishing audio-frequency signals eminating from smoke detectors or other sounds, e.g., an alarm clock or telephone.